xref: /linux/drivers/dma/xilinx/xilinx_dpdma.c (revision d53b8e36925256097a08d7cb749198d85cbf9b2b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Xilinx ZynqMP DPDMA Engine driver
4  *
5  * Copyright (C) 2015 - 2020 Xilinx, Inc.
6  *
7  * Author: Hyun Woo Kwon <hyun.kwon@xilinx.com>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/bits.h>
12 #include <linux/clk.h>
13 #include <linux/debugfs.h>
14 #include <linux/delay.h>
15 #include <linux/dma/xilinx_dpdma.h>
16 #include <linux/dmaengine.h>
17 #include <linux/dmapool.h>
18 #include <linux/interrupt.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_dma.h>
22 #include <linux/platform_device.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/wait.h>
27 
28 #include <dt-bindings/dma/xlnx-zynqmp-dpdma.h>
29 
30 #include "../dmaengine.h"
31 #include "../virt-dma.h"
32 
33 /* DPDMA registers */
34 #define XILINX_DPDMA_ERR_CTRL				0x000
35 #define XILINX_DPDMA_ISR				0x004
36 #define XILINX_DPDMA_IMR				0x008
37 #define XILINX_DPDMA_IEN				0x00c
38 #define XILINX_DPDMA_IDS				0x010
39 #define XILINX_DPDMA_INTR_DESC_DONE(n)			BIT((n) + 0)
40 #define XILINX_DPDMA_INTR_DESC_DONE_MASK		GENMASK(5, 0)
41 #define XILINX_DPDMA_INTR_NO_OSTAND(n)			BIT((n) + 6)
42 #define XILINX_DPDMA_INTR_NO_OSTAND_MASK		GENMASK(11, 6)
43 #define XILINX_DPDMA_INTR_AXI_ERR(n)			BIT((n) + 12)
44 #define XILINX_DPDMA_INTR_AXI_ERR_MASK			GENMASK(17, 12)
45 #define XILINX_DPDMA_INTR_DESC_ERR(n)			BIT((n) + 16)
46 #define XILINX_DPDMA_INTR_DESC_ERR_MASK			GENMASK(23, 18)
47 #define XILINX_DPDMA_INTR_WR_CMD_FIFO_FULL		BIT(24)
48 #define XILINX_DPDMA_INTR_WR_DATA_FIFO_FULL		BIT(25)
49 #define XILINX_DPDMA_INTR_AXI_4K_CROSS			BIT(26)
50 #define XILINX_DPDMA_INTR_VSYNC				BIT(27)
51 #define XILINX_DPDMA_INTR_CHAN_ERR_MASK			0x00041000
52 #define XILINX_DPDMA_INTR_CHAN_ERR			0x00fff000
53 #define XILINX_DPDMA_INTR_GLOBAL_ERR			0x07000000
54 #define XILINX_DPDMA_INTR_ERR_ALL			0x07fff000
55 #define XILINX_DPDMA_INTR_CHAN_MASK			0x00041041
56 #define XILINX_DPDMA_INTR_GLOBAL_MASK			0x0f000000
57 #define XILINX_DPDMA_INTR_ALL				0x0fffffff
58 #define XILINX_DPDMA_EISR				0x014
59 #define XILINX_DPDMA_EIMR				0x018
60 #define XILINX_DPDMA_EIEN				0x01c
61 #define XILINX_DPDMA_EIDS				0x020
62 #define XILINX_DPDMA_EINTR_INV_APB			BIT(0)
63 #define XILINX_DPDMA_EINTR_RD_AXI_ERR(n)		BIT((n) + 1)
64 #define XILINX_DPDMA_EINTR_RD_AXI_ERR_MASK		GENMASK(6, 1)
65 #define XILINX_DPDMA_EINTR_PRE_ERR(n)			BIT((n) + 7)
66 #define XILINX_DPDMA_EINTR_PRE_ERR_MASK			GENMASK(12, 7)
67 #define XILINX_DPDMA_EINTR_CRC_ERR(n)			BIT((n) + 13)
68 #define XILINX_DPDMA_EINTR_CRC_ERR_MASK			GENMASK(18, 13)
69 #define XILINX_DPDMA_EINTR_WR_AXI_ERR(n)		BIT((n) + 19)
70 #define XILINX_DPDMA_EINTR_WR_AXI_ERR_MASK		GENMASK(24, 19)
71 #define XILINX_DPDMA_EINTR_DESC_DONE_ERR(n)		BIT((n) + 25)
72 #define XILINX_DPDMA_EINTR_DESC_DONE_ERR_MASK		GENMASK(30, 25)
73 #define XILINX_DPDMA_EINTR_RD_CMD_FIFO_FULL		BIT(32)
74 #define XILINX_DPDMA_EINTR_CHAN_ERR_MASK		0x02082082
75 #define XILINX_DPDMA_EINTR_CHAN_ERR			0x7ffffffe
76 #define XILINX_DPDMA_EINTR_GLOBAL_ERR			0x80000001
77 #define XILINX_DPDMA_EINTR_ALL				0xffffffff
78 #define XILINX_DPDMA_CNTL				0x100
79 #define XILINX_DPDMA_GBL				0x104
80 #define XILINX_DPDMA_GBL_TRIG_MASK(n)			((n) << 0)
81 #define XILINX_DPDMA_GBL_RETRIG_MASK(n)			((n) << 6)
82 #define XILINX_DPDMA_ALC0_CNTL				0x108
83 #define XILINX_DPDMA_ALC0_STATUS			0x10c
84 #define XILINX_DPDMA_ALC0_MAX				0x110
85 #define XILINX_DPDMA_ALC0_MIN				0x114
86 #define XILINX_DPDMA_ALC0_ACC				0x118
87 #define XILINX_DPDMA_ALC0_ACC_TRAN			0x11c
88 #define XILINX_DPDMA_ALC1_CNTL				0x120
89 #define XILINX_DPDMA_ALC1_STATUS			0x124
90 #define XILINX_DPDMA_ALC1_MAX				0x128
91 #define XILINX_DPDMA_ALC1_MIN				0x12c
92 #define XILINX_DPDMA_ALC1_ACC				0x130
93 #define XILINX_DPDMA_ALC1_ACC_TRAN			0x134
94 
95 /* Channel register */
96 #define XILINX_DPDMA_CH_BASE				0x200
97 #define XILINX_DPDMA_CH_OFFSET				0x100
98 #define XILINX_DPDMA_CH_DESC_START_ADDRE		0x000
99 #define XILINX_DPDMA_CH_DESC_START_ADDRE_MASK		GENMASK(15, 0)
100 #define XILINX_DPDMA_CH_DESC_START_ADDR			0x004
101 #define XILINX_DPDMA_CH_DESC_NEXT_ADDRE			0x008
102 #define XILINX_DPDMA_CH_DESC_NEXT_ADDR			0x00c
103 #define XILINX_DPDMA_CH_PYLD_CUR_ADDRE			0x010
104 #define XILINX_DPDMA_CH_PYLD_CUR_ADDR			0x014
105 #define XILINX_DPDMA_CH_CNTL				0x018
106 #define XILINX_DPDMA_CH_CNTL_ENABLE			BIT(0)
107 #define XILINX_DPDMA_CH_CNTL_PAUSE			BIT(1)
108 #define XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK		GENMASK(5, 2)
109 #define XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK		GENMASK(9, 6)
110 #define XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK		GENMASK(13, 10)
111 #define XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS		11
112 #define XILINX_DPDMA_CH_STATUS				0x01c
113 #define XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK		GENMASK(24, 21)
114 #define XILINX_DPDMA_CH_VDO				0x020
115 #define XILINX_DPDMA_CH_PYLD_SZ				0x024
116 #define XILINX_DPDMA_CH_DESC_ID				0x028
117 #define XILINX_DPDMA_CH_DESC_ID_MASK			GENMASK(15, 0)
118 
119 /* DPDMA descriptor fields */
120 #define XILINX_DPDMA_DESC_CONTROL_PREEMBLE		0xa5
121 #define XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR		BIT(8)
122 #define XILINX_DPDMA_DESC_CONTROL_DESC_UPDATE		BIT(9)
123 #define XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE		BIT(10)
124 #define XILINX_DPDMA_DESC_CONTROL_FRAG_MODE		BIT(18)
125 #define XILINX_DPDMA_DESC_CONTROL_LAST			BIT(19)
126 #define XILINX_DPDMA_DESC_CONTROL_ENABLE_CRC		BIT(20)
127 #define XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME		BIT(21)
128 #define XILINX_DPDMA_DESC_ID_MASK			GENMASK(15, 0)
129 #define XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK	GENMASK(17, 0)
130 #define XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK	GENMASK(31, 18)
131 #define XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK	GENMASK(15, 0)
132 #define XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK	GENMASK(31, 16)
133 
134 #define XILINX_DPDMA_ALIGN_BYTES			256
135 #define XILINX_DPDMA_LINESIZE_ALIGN_BITS		128
136 
137 #define XILINX_DPDMA_NUM_CHAN				6
138 
139 struct xilinx_dpdma_chan;
140 
141 /**
142  * struct xilinx_dpdma_hw_desc - DPDMA hardware descriptor
143  * @control: control configuration field
144  * @desc_id: descriptor ID
145  * @xfer_size: transfer size
146  * @hsize_stride: horizontal size and stride
147  * @timestamp_lsb: LSB of time stamp
148  * @timestamp_msb: MSB of time stamp
149  * @addr_ext: upper 16 bit of 48 bit address (next_desc and src_addr)
150  * @next_desc: next descriptor 32 bit address
151  * @src_addr: payload source address (1st page, 32 LSB)
152  * @addr_ext_23: payload source address (3nd and 3rd pages, 16 LSBs)
153  * @addr_ext_45: payload source address (4th and 5th pages, 16 LSBs)
154  * @src_addr2: payload source address (2nd page, 32 LSB)
155  * @src_addr3: payload source address (3rd page, 32 LSB)
156  * @src_addr4: payload source address (4th page, 32 LSB)
157  * @src_addr5: payload source address (5th page, 32 LSB)
158  * @crc: descriptor CRC
159  */
160 struct xilinx_dpdma_hw_desc {
161 	u32 control;
162 	u32 desc_id;
163 	u32 xfer_size;
164 	u32 hsize_stride;
165 	u32 timestamp_lsb;
166 	u32 timestamp_msb;
167 	u32 addr_ext;
168 	u32 next_desc;
169 	u32 src_addr;
170 	u32 addr_ext_23;
171 	u32 addr_ext_45;
172 	u32 src_addr2;
173 	u32 src_addr3;
174 	u32 src_addr4;
175 	u32 src_addr5;
176 	u32 crc;
177 } __aligned(XILINX_DPDMA_ALIGN_BYTES);
178 
179 /**
180  * struct xilinx_dpdma_sw_desc - DPDMA software descriptor
181  * @hw: DPDMA hardware descriptor
182  * @node: list node for software descriptors
183  * @dma_addr: DMA address of the software descriptor
184  */
185 struct xilinx_dpdma_sw_desc {
186 	struct xilinx_dpdma_hw_desc hw;
187 	struct list_head node;
188 	dma_addr_t dma_addr;
189 };
190 
191 /**
192  * struct xilinx_dpdma_tx_desc - DPDMA transaction descriptor
193  * @vdesc: virtual DMA descriptor
194  * @chan: DMA channel
195  * @descriptors: list of software descriptors
196  * @error: an error has been detected with this descriptor
197  */
198 struct xilinx_dpdma_tx_desc {
199 	struct virt_dma_desc vdesc;
200 	struct xilinx_dpdma_chan *chan;
201 	struct list_head descriptors;
202 	bool error;
203 };
204 
205 #define to_dpdma_tx_desc(_desc) \
206 	container_of(_desc, struct xilinx_dpdma_tx_desc, vdesc)
207 
208 /**
209  * struct xilinx_dpdma_chan - DPDMA channel
210  * @vchan: virtual DMA channel
211  * @reg: register base address
212  * @id: channel ID
213  * @wait_to_stop: queue to wait for outstanding transacitons before stopping
214  * @running: true if the channel is running
215  * @first_frame: flag for the first frame of stream
216  * @video_group: flag if multi-channel operation is needed for video channels
217  * @lock: lock to access struct xilinx_dpdma_chan. Must be taken before
218  *        @vchan.lock, if both are to be held.
219  * @desc_pool: descriptor allocation pool
220  * @err_task: error IRQ bottom half handler
221  * @desc: References to descriptors being processed
222  * @desc.pending: Descriptor schedule to the hardware, pending execution
223  * @desc.active: Descriptor being executed by the hardware
224  * @xdev: DPDMA device
225  */
226 struct xilinx_dpdma_chan {
227 	struct virt_dma_chan vchan;
228 	void __iomem *reg;
229 	unsigned int id;
230 
231 	wait_queue_head_t wait_to_stop;
232 	bool running;
233 	bool first_frame;
234 	bool video_group;
235 
236 	spinlock_t lock; /* lock to access struct xilinx_dpdma_chan */
237 	struct dma_pool *desc_pool;
238 	struct tasklet_struct err_task;
239 
240 	struct {
241 		struct xilinx_dpdma_tx_desc *pending;
242 		struct xilinx_dpdma_tx_desc *active;
243 	} desc;
244 
245 	struct xilinx_dpdma_device *xdev;
246 };
247 
248 #define to_xilinx_chan(_chan) \
249 	container_of(_chan, struct xilinx_dpdma_chan, vchan.chan)
250 
251 /**
252  * struct xilinx_dpdma_device - DPDMA device
253  * @common: generic dma device structure
254  * @reg: register base address
255  * @dev: generic device structure
256  * @irq: the interrupt number
257  * @axi_clk: axi clock
258  * @chan: DPDMA channels
259  * @ext_addr: flag for 64 bit system (48 bit addressing)
260  */
261 struct xilinx_dpdma_device {
262 	struct dma_device common;
263 	void __iomem *reg;
264 	struct device *dev;
265 	int irq;
266 
267 	struct clk *axi_clk;
268 	struct xilinx_dpdma_chan *chan[XILINX_DPDMA_NUM_CHAN];
269 
270 	bool ext_addr;
271 };
272 
273 /* -----------------------------------------------------------------------------
274  * DebugFS
275  */
276 #define XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE	32
277 #define XILINX_DPDMA_DEBUGFS_UINT16_MAX_STR	"65535"
278 
279 /* Match xilinx_dpdma_testcases vs dpdma_debugfs_reqs[] entry */
280 enum xilinx_dpdma_testcases {
281 	DPDMA_TC_INTR_DONE,
282 	DPDMA_TC_NONE
283 };
284 
285 struct xilinx_dpdma_debugfs {
286 	enum xilinx_dpdma_testcases testcase;
287 	u16 xilinx_dpdma_irq_done_count;
288 	unsigned int chan_id;
289 };
290 
291 static struct xilinx_dpdma_debugfs dpdma_debugfs;
292 struct xilinx_dpdma_debugfs_request {
293 	const char *name;
294 	enum xilinx_dpdma_testcases tc;
295 	ssize_t (*read)(char *buf);
296 	int (*write)(char *args);
297 };
298 
299 static void xilinx_dpdma_debugfs_desc_done_irq(struct xilinx_dpdma_chan *chan)
300 {
301 	if (IS_ENABLED(CONFIG_DEBUG_FS) && chan->id == dpdma_debugfs.chan_id)
302 		dpdma_debugfs.xilinx_dpdma_irq_done_count++;
303 }
304 
305 static ssize_t xilinx_dpdma_debugfs_desc_done_irq_read(char *buf)
306 {
307 	size_t out_str_len;
308 
309 	dpdma_debugfs.testcase = DPDMA_TC_NONE;
310 
311 	out_str_len = strlen(XILINX_DPDMA_DEBUGFS_UINT16_MAX_STR);
312 	out_str_len = min_t(size_t, XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE,
313 			    out_str_len + 1);
314 	snprintf(buf, out_str_len, "%d",
315 		 dpdma_debugfs.xilinx_dpdma_irq_done_count);
316 
317 	return 0;
318 }
319 
320 static int xilinx_dpdma_debugfs_desc_done_irq_write(char *args)
321 {
322 	char *arg;
323 	int ret;
324 	u32 id;
325 
326 	arg = strsep(&args, " ");
327 	if (!arg || strncasecmp(arg, "start", 5))
328 		return -EINVAL;
329 
330 	arg = strsep(&args, " ");
331 	if (!arg)
332 		return -EINVAL;
333 
334 	ret = kstrtou32(arg, 0, &id);
335 	if (ret < 0)
336 		return ret;
337 
338 	if (id < ZYNQMP_DPDMA_VIDEO0 || id > ZYNQMP_DPDMA_AUDIO1)
339 		return -EINVAL;
340 
341 	dpdma_debugfs.testcase = DPDMA_TC_INTR_DONE;
342 	dpdma_debugfs.xilinx_dpdma_irq_done_count = 0;
343 	dpdma_debugfs.chan_id = id;
344 
345 	return 0;
346 }
347 
348 /* Match xilinx_dpdma_testcases vs dpdma_debugfs_reqs[] entry */
349 static struct xilinx_dpdma_debugfs_request dpdma_debugfs_reqs[] = {
350 	{
351 		.name = "DESCRIPTOR_DONE_INTR",
352 		.tc = DPDMA_TC_INTR_DONE,
353 		.read = xilinx_dpdma_debugfs_desc_done_irq_read,
354 		.write = xilinx_dpdma_debugfs_desc_done_irq_write,
355 	},
356 };
357 
358 static ssize_t xilinx_dpdma_debugfs_read(struct file *f, char __user *buf,
359 					 size_t size, loff_t *pos)
360 {
361 	enum xilinx_dpdma_testcases testcase;
362 	char *kern_buff;
363 	int ret = 0;
364 
365 	if (*pos != 0 || size <= 0)
366 		return -EINVAL;
367 
368 	kern_buff = kzalloc(XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE, GFP_KERNEL);
369 	if (!kern_buff) {
370 		dpdma_debugfs.testcase = DPDMA_TC_NONE;
371 		return -ENOMEM;
372 	}
373 
374 	testcase = READ_ONCE(dpdma_debugfs.testcase);
375 	if (testcase != DPDMA_TC_NONE) {
376 		ret = dpdma_debugfs_reqs[testcase].read(kern_buff);
377 		if (ret < 0)
378 			goto done;
379 	} else {
380 		strscpy(kern_buff, "No testcase executed",
381 			XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE);
382 	}
383 
384 	size = min(size, strlen(kern_buff));
385 	if (copy_to_user(buf, kern_buff, size))
386 		ret = -EFAULT;
387 
388 done:
389 	kfree(kern_buff);
390 	if (ret)
391 		return ret;
392 
393 	*pos = size + 1;
394 	return size;
395 }
396 
397 static ssize_t xilinx_dpdma_debugfs_write(struct file *f,
398 					  const char __user *buf, size_t size,
399 					  loff_t *pos)
400 {
401 	char *kern_buff, *kern_buff_start;
402 	char *testcase;
403 	unsigned int i;
404 	int ret;
405 
406 	if (*pos != 0 || size <= 0)
407 		return -EINVAL;
408 
409 	/* Supporting single instance of test as of now. */
410 	if (dpdma_debugfs.testcase != DPDMA_TC_NONE)
411 		return -EBUSY;
412 
413 	kern_buff = kzalloc(size, GFP_KERNEL);
414 	if (!kern_buff)
415 		return -ENOMEM;
416 	kern_buff_start = kern_buff;
417 
418 	ret = strncpy_from_user(kern_buff, buf, size);
419 	if (ret < 0)
420 		goto done;
421 
422 	/* Read the testcase name from a user request. */
423 	testcase = strsep(&kern_buff, " ");
424 
425 	for (i = 0; i < ARRAY_SIZE(dpdma_debugfs_reqs); i++) {
426 		if (!strcasecmp(testcase, dpdma_debugfs_reqs[i].name))
427 			break;
428 	}
429 
430 	if (i == ARRAY_SIZE(dpdma_debugfs_reqs)) {
431 		ret = -EINVAL;
432 		goto done;
433 	}
434 
435 	ret = dpdma_debugfs_reqs[i].write(kern_buff);
436 	if (ret < 0)
437 		goto done;
438 
439 	ret = size;
440 
441 done:
442 	kfree(kern_buff_start);
443 	return ret;
444 }
445 
446 static const struct file_operations fops_xilinx_dpdma_dbgfs = {
447 	.owner = THIS_MODULE,
448 	.read = xilinx_dpdma_debugfs_read,
449 	.write = xilinx_dpdma_debugfs_write,
450 };
451 
452 static void xilinx_dpdma_debugfs_init(struct xilinx_dpdma_device *xdev)
453 {
454 	struct dentry *dent;
455 
456 	dpdma_debugfs.testcase = DPDMA_TC_NONE;
457 
458 	dent = debugfs_create_file("testcase", 0444, xdev->common.dbg_dev_root,
459 				   NULL, &fops_xilinx_dpdma_dbgfs);
460 	if (IS_ERR(dent))
461 		dev_err(xdev->dev, "Failed to create debugfs testcase file\n");
462 }
463 
464 /* -----------------------------------------------------------------------------
465  * I/O Accessors
466  */
467 
468 static inline u32 dpdma_read(void __iomem *base, u32 offset)
469 {
470 	return ioread32(base + offset);
471 }
472 
473 static inline void dpdma_write(void __iomem *base, u32 offset, u32 val)
474 {
475 	iowrite32(val, base + offset);
476 }
477 
478 static inline void dpdma_clr(void __iomem *base, u32 offset, u32 clr)
479 {
480 	dpdma_write(base, offset, dpdma_read(base, offset) & ~clr);
481 }
482 
483 static inline void dpdma_set(void __iomem *base, u32 offset, u32 set)
484 {
485 	dpdma_write(base, offset, dpdma_read(base, offset) | set);
486 }
487 
488 /* -----------------------------------------------------------------------------
489  * Descriptor Operations
490  */
491 
492 /**
493  * xilinx_dpdma_sw_desc_set_dma_addrs - Set DMA addresses in the descriptor
494  * @xdev: DPDMA device
495  * @sw_desc: The software descriptor in which to set DMA addresses
496  * @prev: The previous descriptor
497  * @dma_addr: array of dma addresses
498  * @num_src_addr: number of addresses in @dma_addr
499  *
500  * Set all the DMA addresses in the hardware descriptor corresponding to @dev
501  * from @dma_addr. If a previous descriptor is specified in @prev, its next
502  * descriptor DMA address is set to the DMA address of @sw_desc. @prev may be
503  * identical to @sw_desc for cyclic transfers.
504  */
505 static void xilinx_dpdma_sw_desc_set_dma_addrs(struct xilinx_dpdma_device *xdev,
506 					       struct xilinx_dpdma_sw_desc *sw_desc,
507 					       struct xilinx_dpdma_sw_desc *prev,
508 					       dma_addr_t dma_addr[],
509 					       unsigned int num_src_addr)
510 {
511 	struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
512 	unsigned int i;
513 
514 	hw_desc->src_addr = lower_32_bits(dma_addr[0]);
515 	if (xdev->ext_addr)
516 		hw_desc->addr_ext |=
517 			FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK,
518 				   upper_32_bits(dma_addr[0]));
519 
520 	for (i = 1; i < num_src_addr; i++) {
521 		u32 *addr = &hw_desc->src_addr2;
522 
523 		addr[i - 1] = lower_32_bits(dma_addr[i]);
524 
525 		if (xdev->ext_addr) {
526 			u32 *addr_ext = &hw_desc->addr_ext_23;
527 			u32 addr_msb;
528 
529 			addr_msb = upper_32_bits(dma_addr[i]) & GENMASK(15, 0);
530 			addr_msb <<= 16 * ((i - 1) % 2);
531 			addr_ext[(i - 1) / 2] |= addr_msb;
532 		}
533 	}
534 
535 	if (!prev)
536 		return;
537 
538 	prev->hw.next_desc = lower_32_bits(sw_desc->dma_addr);
539 	if (xdev->ext_addr)
540 		prev->hw.addr_ext |=
541 			FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK,
542 				   upper_32_bits(sw_desc->dma_addr));
543 }
544 
545 /**
546  * xilinx_dpdma_chan_alloc_sw_desc - Allocate a software descriptor
547  * @chan: DPDMA channel
548  *
549  * Allocate a software descriptor from the channel's descriptor pool.
550  *
551  * Return: a software descriptor or NULL.
552  */
553 static struct xilinx_dpdma_sw_desc *
554 xilinx_dpdma_chan_alloc_sw_desc(struct xilinx_dpdma_chan *chan)
555 {
556 	struct xilinx_dpdma_sw_desc *sw_desc;
557 	dma_addr_t dma_addr;
558 
559 	sw_desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &dma_addr);
560 	if (!sw_desc)
561 		return NULL;
562 
563 	sw_desc->dma_addr = dma_addr;
564 
565 	return sw_desc;
566 }
567 
568 /**
569  * xilinx_dpdma_chan_free_sw_desc - Free a software descriptor
570  * @chan: DPDMA channel
571  * @sw_desc: software descriptor to free
572  *
573  * Free a software descriptor from the channel's descriptor pool.
574  */
575 static void
576 xilinx_dpdma_chan_free_sw_desc(struct xilinx_dpdma_chan *chan,
577 			       struct xilinx_dpdma_sw_desc *sw_desc)
578 {
579 	dma_pool_free(chan->desc_pool, sw_desc, sw_desc->dma_addr);
580 }
581 
582 /**
583  * xilinx_dpdma_chan_dump_tx_desc - Dump a tx descriptor
584  * @chan: DPDMA channel
585  * @tx_desc: tx descriptor to dump
586  *
587  * Dump contents of a tx descriptor
588  */
589 static void xilinx_dpdma_chan_dump_tx_desc(struct xilinx_dpdma_chan *chan,
590 					   struct xilinx_dpdma_tx_desc *tx_desc)
591 {
592 	struct xilinx_dpdma_sw_desc *sw_desc;
593 	struct device *dev = chan->xdev->dev;
594 	unsigned int i = 0;
595 
596 	dev_dbg(dev, "------- TX descriptor dump start -------\n");
597 	dev_dbg(dev, "------- channel ID = %d -------\n", chan->id);
598 
599 	list_for_each_entry(sw_desc, &tx_desc->descriptors, node) {
600 		struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
601 
602 		dev_dbg(dev, "------- HW descriptor %d -------\n", i++);
603 		dev_dbg(dev, "descriptor DMA addr: %pad\n", &sw_desc->dma_addr);
604 		dev_dbg(dev, "control: 0x%08x\n", hw_desc->control);
605 		dev_dbg(dev, "desc_id: 0x%08x\n", hw_desc->desc_id);
606 		dev_dbg(dev, "xfer_size: 0x%08x\n", hw_desc->xfer_size);
607 		dev_dbg(dev, "hsize_stride: 0x%08x\n", hw_desc->hsize_stride);
608 		dev_dbg(dev, "timestamp_lsb: 0x%08x\n", hw_desc->timestamp_lsb);
609 		dev_dbg(dev, "timestamp_msb: 0x%08x\n", hw_desc->timestamp_msb);
610 		dev_dbg(dev, "addr_ext: 0x%08x\n", hw_desc->addr_ext);
611 		dev_dbg(dev, "next_desc: 0x%08x\n", hw_desc->next_desc);
612 		dev_dbg(dev, "src_addr: 0x%08x\n", hw_desc->src_addr);
613 		dev_dbg(dev, "addr_ext_23: 0x%08x\n", hw_desc->addr_ext_23);
614 		dev_dbg(dev, "addr_ext_45: 0x%08x\n", hw_desc->addr_ext_45);
615 		dev_dbg(dev, "src_addr2: 0x%08x\n", hw_desc->src_addr2);
616 		dev_dbg(dev, "src_addr3: 0x%08x\n", hw_desc->src_addr3);
617 		dev_dbg(dev, "src_addr4: 0x%08x\n", hw_desc->src_addr4);
618 		dev_dbg(dev, "src_addr5: 0x%08x\n", hw_desc->src_addr5);
619 		dev_dbg(dev, "crc: 0x%08x\n", hw_desc->crc);
620 	}
621 
622 	dev_dbg(dev, "------- TX descriptor dump end -------\n");
623 }
624 
625 /**
626  * xilinx_dpdma_chan_alloc_tx_desc - Allocate a transaction descriptor
627  * @chan: DPDMA channel
628  *
629  * Allocate a tx descriptor.
630  *
631  * Return: a tx descriptor or NULL.
632  */
633 static struct xilinx_dpdma_tx_desc *
634 xilinx_dpdma_chan_alloc_tx_desc(struct xilinx_dpdma_chan *chan)
635 {
636 	struct xilinx_dpdma_tx_desc *tx_desc;
637 
638 	tx_desc = kzalloc(sizeof(*tx_desc), GFP_NOWAIT);
639 	if (!tx_desc)
640 		return NULL;
641 
642 	INIT_LIST_HEAD(&tx_desc->descriptors);
643 	tx_desc->chan = chan;
644 	tx_desc->error = false;
645 
646 	return tx_desc;
647 }
648 
649 /**
650  * xilinx_dpdma_chan_free_tx_desc - Free a virtual DMA descriptor
651  * @vdesc: virtual DMA descriptor
652  *
653  * Free the virtual DMA descriptor @vdesc including its software descriptors.
654  */
655 static void xilinx_dpdma_chan_free_tx_desc(struct virt_dma_desc *vdesc)
656 {
657 	struct xilinx_dpdma_sw_desc *sw_desc, *next;
658 	struct xilinx_dpdma_tx_desc *desc;
659 
660 	if (!vdesc)
661 		return;
662 
663 	desc = to_dpdma_tx_desc(vdesc);
664 
665 	list_for_each_entry_safe(sw_desc, next, &desc->descriptors, node) {
666 		list_del(&sw_desc->node);
667 		xilinx_dpdma_chan_free_sw_desc(desc->chan, sw_desc);
668 	}
669 
670 	kfree(desc);
671 }
672 
673 /**
674  * xilinx_dpdma_chan_prep_interleaved_dma - Prepare an interleaved dma
675  *					    descriptor
676  * @chan: DPDMA channel
677  * @xt: dma interleaved template
678  *
679  * Prepare a tx descriptor including internal software/hardware descriptors
680  * based on @xt.
681  *
682  * Return: A DPDMA TX descriptor on success, or NULL.
683  */
684 static struct xilinx_dpdma_tx_desc *
685 xilinx_dpdma_chan_prep_interleaved_dma(struct xilinx_dpdma_chan *chan,
686 				       struct dma_interleaved_template *xt)
687 {
688 	struct xilinx_dpdma_tx_desc *tx_desc;
689 	struct xilinx_dpdma_sw_desc *sw_desc;
690 	struct xilinx_dpdma_hw_desc *hw_desc;
691 	size_t hsize = xt->sgl[0].size;
692 	size_t stride = hsize + xt->sgl[0].icg;
693 
694 	if (!IS_ALIGNED(xt->src_start, XILINX_DPDMA_ALIGN_BYTES)) {
695 		dev_err(chan->xdev->dev,
696 			"chan%u: buffer should be aligned at %d B\n",
697 			chan->id, XILINX_DPDMA_ALIGN_BYTES);
698 		return NULL;
699 	}
700 
701 	tx_desc = xilinx_dpdma_chan_alloc_tx_desc(chan);
702 	if (!tx_desc)
703 		return NULL;
704 
705 	sw_desc = xilinx_dpdma_chan_alloc_sw_desc(chan);
706 	if (!sw_desc) {
707 		xilinx_dpdma_chan_free_tx_desc(&tx_desc->vdesc);
708 		return NULL;
709 	}
710 
711 	xilinx_dpdma_sw_desc_set_dma_addrs(chan->xdev, sw_desc, sw_desc,
712 					   &xt->src_start, 1);
713 
714 	hw_desc = &sw_desc->hw;
715 	hsize = ALIGN(hsize, XILINX_DPDMA_LINESIZE_ALIGN_BITS / 8);
716 	hw_desc->xfer_size = hsize * xt->numf;
717 	hw_desc->hsize_stride =
718 		FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK, hsize) |
719 		FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK,
720 			   stride / 16);
721 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_PREEMBLE;
722 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR;
723 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE;
724 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME;
725 
726 	list_add_tail(&sw_desc->node, &tx_desc->descriptors);
727 
728 	return tx_desc;
729 }
730 
731 /* -----------------------------------------------------------------------------
732  * DPDMA Channel Operations
733  */
734 
735 /**
736  * xilinx_dpdma_chan_enable - Enable the channel
737  * @chan: DPDMA channel
738  *
739  * Enable the channel and its interrupts. Set the QoS values for video class.
740  */
741 static void xilinx_dpdma_chan_enable(struct xilinx_dpdma_chan *chan)
742 {
743 	u32 reg;
744 
745 	reg = (XILINX_DPDMA_INTR_CHAN_MASK << chan->id)
746 	    | XILINX_DPDMA_INTR_GLOBAL_MASK;
747 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
748 	reg = (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id)
749 	    | XILINX_DPDMA_INTR_GLOBAL_ERR;
750 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
751 
752 	reg = XILINX_DPDMA_CH_CNTL_ENABLE
753 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK,
754 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
755 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK,
756 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
757 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK,
758 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS);
759 	dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, reg);
760 }
761 
762 /**
763  * xilinx_dpdma_chan_disable - Disable the channel
764  * @chan: DPDMA channel
765  *
766  * Disable the channel and its interrupts.
767  */
768 static void xilinx_dpdma_chan_disable(struct xilinx_dpdma_chan *chan)
769 {
770 	u32 reg;
771 
772 	reg = XILINX_DPDMA_INTR_CHAN_MASK << chan->id;
773 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
774 	reg = XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id;
775 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
776 
777 	dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_ENABLE);
778 }
779 
780 /**
781  * xilinx_dpdma_chan_pause - Pause the channel
782  * @chan: DPDMA channel
783  *
784  * Pause the channel.
785  */
786 static void xilinx_dpdma_chan_pause(struct xilinx_dpdma_chan *chan)
787 {
788 	dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
789 }
790 
791 /**
792  * xilinx_dpdma_chan_unpause - Unpause the channel
793  * @chan: DPDMA channel
794  *
795  * Unpause the channel.
796  */
797 static void xilinx_dpdma_chan_unpause(struct xilinx_dpdma_chan *chan)
798 {
799 	dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
800 }
801 
802 static u32 xilinx_dpdma_chan_video_group_ready(struct xilinx_dpdma_chan *chan)
803 {
804 	struct xilinx_dpdma_device *xdev = chan->xdev;
805 	u32 channels = 0;
806 	unsigned int i;
807 
808 	for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
809 		if (xdev->chan[i]->video_group && !xdev->chan[i]->running)
810 			return 0;
811 
812 		if (xdev->chan[i]->video_group)
813 			channels |= BIT(i);
814 	}
815 
816 	return channels;
817 }
818 
819 /**
820  * xilinx_dpdma_chan_queue_transfer - Queue the next transfer
821  * @chan: DPDMA channel
822  *
823  * Queue the next descriptor, if any, to the hardware. If the channel is
824  * stopped, start it first. Otherwise retrigger it with the next descriptor.
825  */
826 static void xilinx_dpdma_chan_queue_transfer(struct xilinx_dpdma_chan *chan)
827 {
828 	struct xilinx_dpdma_device *xdev = chan->xdev;
829 	struct xilinx_dpdma_sw_desc *sw_desc;
830 	struct xilinx_dpdma_tx_desc *desc;
831 	struct virt_dma_desc *vdesc;
832 	u32 reg, channels;
833 	bool first_frame;
834 
835 	lockdep_assert_held(&chan->lock);
836 
837 	if (chan->desc.pending)
838 		return;
839 
840 	if (!chan->running) {
841 		xilinx_dpdma_chan_unpause(chan);
842 		xilinx_dpdma_chan_enable(chan);
843 		chan->first_frame = true;
844 		chan->running = true;
845 	}
846 
847 	vdesc = vchan_next_desc(&chan->vchan);
848 	if (!vdesc)
849 		return;
850 
851 	desc = to_dpdma_tx_desc(vdesc);
852 	chan->desc.pending = desc;
853 	list_del(&desc->vdesc.node);
854 
855 	/*
856 	 * Assign the cookie to descriptors in this transaction. Only 16 bit
857 	 * will be used, but it should be enough.
858 	 */
859 	list_for_each_entry(sw_desc, &desc->descriptors, node)
860 		sw_desc->hw.desc_id = desc->vdesc.tx.cookie
861 				    & XILINX_DPDMA_CH_DESC_ID_MASK;
862 
863 	sw_desc = list_first_entry(&desc->descriptors,
864 				   struct xilinx_dpdma_sw_desc, node);
865 	dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR,
866 		    lower_32_bits(sw_desc->dma_addr));
867 	if (xdev->ext_addr)
868 		dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE,
869 			    FIELD_PREP(XILINX_DPDMA_CH_DESC_START_ADDRE_MASK,
870 				       upper_32_bits(sw_desc->dma_addr)));
871 
872 	first_frame = chan->first_frame;
873 	chan->first_frame = false;
874 
875 	if (chan->video_group) {
876 		channels = xilinx_dpdma_chan_video_group_ready(chan);
877 		/*
878 		 * Trigger the transfer only when all channels in the group are
879 		 * ready.
880 		 */
881 		if (!channels)
882 			return;
883 	} else {
884 		channels = BIT(chan->id);
885 	}
886 
887 	if (first_frame)
888 		reg = XILINX_DPDMA_GBL_TRIG_MASK(channels);
889 	else
890 		reg = XILINX_DPDMA_GBL_RETRIG_MASK(channels);
891 
892 	dpdma_write(xdev->reg, XILINX_DPDMA_GBL, reg);
893 }
894 
895 /**
896  * xilinx_dpdma_chan_ostand - Number of outstanding transactions
897  * @chan: DPDMA channel
898  *
899  * Read and return the number of outstanding transactions from register.
900  *
901  * Return: Number of outstanding transactions from the status register.
902  */
903 static u32 xilinx_dpdma_chan_ostand(struct xilinx_dpdma_chan *chan)
904 {
905 	return FIELD_GET(XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK,
906 			 dpdma_read(chan->reg, XILINX_DPDMA_CH_STATUS));
907 }
908 
909 /**
910  * xilinx_dpdma_chan_notify_no_ostand - Notify no outstanding transaction event
911  * @chan: DPDMA channel
912  *
913  * Notify waiters for no outstanding event, so waiters can stop the channel
914  * safely. This function is supposed to be called when 'no outstanding'
915  * interrupt is generated. The 'no outstanding' interrupt is disabled and
916  * should be re-enabled when this event is handled. If the channel status
917  * register still shows some number of outstanding transactions, the interrupt
918  * remains enabled.
919  *
920  * Return: 0 on success. On failure, -EWOULDBLOCK if there's still outstanding
921  * transaction(s).
922  */
923 static int xilinx_dpdma_chan_notify_no_ostand(struct xilinx_dpdma_chan *chan)
924 {
925 	u32 cnt;
926 
927 	cnt = xilinx_dpdma_chan_ostand(chan);
928 	if (cnt) {
929 		dev_dbg(chan->xdev->dev,
930 			"chan%u: %d outstanding transactions\n",
931 			chan->id, cnt);
932 		return -EWOULDBLOCK;
933 	}
934 
935 	/* Disable 'no outstanding' interrupt */
936 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IDS,
937 		    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
938 	wake_up(&chan->wait_to_stop);
939 
940 	return 0;
941 }
942 
943 /**
944  * xilinx_dpdma_chan_wait_no_ostand - Wait for the no outstanding irq
945  * @chan: DPDMA channel
946  *
947  * Wait for the no outstanding transaction interrupt. This functions can sleep
948  * for 50ms.
949  *
950  * Return: 0 on success. On failure, -ETIMEOUT for time out, or the error code
951  * from wait_event_interruptible_timeout().
952  */
953 static int xilinx_dpdma_chan_wait_no_ostand(struct xilinx_dpdma_chan *chan)
954 {
955 	int ret;
956 
957 	/* Wait for a no outstanding transaction interrupt upto 50msec */
958 	ret = wait_event_interruptible_timeout(chan->wait_to_stop,
959 					       !xilinx_dpdma_chan_ostand(chan),
960 					       msecs_to_jiffies(50));
961 	if (ret > 0) {
962 		dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
963 			    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
964 		return 0;
965 	}
966 
967 	dev_err(chan->xdev->dev, "chan%u: not ready to stop: %d trans\n",
968 		chan->id, xilinx_dpdma_chan_ostand(chan));
969 
970 	if (ret == 0)
971 		return -ETIMEDOUT;
972 
973 	return ret;
974 }
975 
976 /**
977  * xilinx_dpdma_chan_poll_no_ostand - Poll the outstanding transaction status
978  * @chan: DPDMA channel
979  *
980  * Poll the outstanding transaction status, and return when there's no
981  * outstanding transaction. This functions can be used in the interrupt context
982  * or where the atomicity is required. Calling thread may wait more than 50ms.
983  *
984  * Return: 0 on success, or -ETIMEDOUT.
985  */
986 static int xilinx_dpdma_chan_poll_no_ostand(struct xilinx_dpdma_chan *chan)
987 {
988 	u32 cnt, loop = 50000;
989 
990 	/* Poll at least for 50ms (20 fps). */
991 	do {
992 		cnt = xilinx_dpdma_chan_ostand(chan);
993 		udelay(1);
994 	} while (loop-- > 0 && cnt);
995 
996 	if (loop) {
997 		dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
998 			    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
999 		return 0;
1000 	}
1001 
1002 	dev_err(chan->xdev->dev, "chan%u: not ready to stop: %d trans\n",
1003 		chan->id, xilinx_dpdma_chan_ostand(chan));
1004 
1005 	return -ETIMEDOUT;
1006 }
1007 
1008 /**
1009  * xilinx_dpdma_chan_stop - Stop the channel
1010  * @chan: DPDMA channel
1011  *
1012  * Stop a previously paused channel by first waiting for completion of all
1013  * outstanding transaction and then disabling the channel.
1014  *
1015  * Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
1016  */
1017 static int xilinx_dpdma_chan_stop(struct xilinx_dpdma_chan *chan)
1018 {
1019 	unsigned long flags;
1020 	int ret;
1021 
1022 	ret = xilinx_dpdma_chan_wait_no_ostand(chan);
1023 	if (ret)
1024 		return ret;
1025 
1026 	spin_lock_irqsave(&chan->lock, flags);
1027 	xilinx_dpdma_chan_disable(chan);
1028 	chan->running = false;
1029 	spin_unlock_irqrestore(&chan->lock, flags);
1030 
1031 	return 0;
1032 }
1033 
1034 /**
1035  * xilinx_dpdma_chan_done_irq - Handle hardware descriptor completion
1036  * @chan: DPDMA channel
1037  *
1038  * Handle completion of the currently active descriptor (@chan->desc.active). As
1039  * we currently support cyclic transfers only, this just invokes the cyclic
1040  * callback. The descriptor will be completed at the VSYNC interrupt when a new
1041  * descriptor replaces it.
1042  */
1043 static void xilinx_dpdma_chan_done_irq(struct xilinx_dpdma_chan *chan)
1044 {
1045 	struct xilinx_dpdma_tx_desc *active;
1046 
1047 	spin_lock(&chan->lock);
1048 
1049 	xilinx_dpdma_debugfs_desc_done_irq(chan);
1050 
1051 	active = chan->desc.active;
1052 	if (active)
1053 		vchan_cyclic_callback(&active->vdesc);
1054 	else
1055 		dev_warn(chan->xdev->dev,
1056 			 "chan%u: DONE IRQ with no active descriptor!\n",
1057 			 chan->id);
1058 
1059 	spin_unlock(&chan->lock);
1060 }
1061 
1062 /**
1063  * xilinx_dpdma_chan_vsync_irq - Handle hardware descriptor scheduling
1064  * @chan: DPDMA channel
1065  *
1066  * At VSYNC the active descriptor may have been replaced by the pending
1067  * descriptor. Detect this through the DESC_ID and perform appropriate
1068  * bookkeeping.
1069  */
1070 static void xilinx_dpdma_chan_vsync_irq(struct  xilinx_dpdma_chan *chan)
1071 {
1072 	struct xilinx_dpdma_tx_desc *pending;
1073 	struct xilinx_dpdma_sw_desc *sw_desc;
1074 	u32 desc_id;
1075 
1076 	spin_lock(&chan->lock);
1077 
1078 	pending = chan->desc.pending;
1079 	if (!chan->running || !pending)
1080 		goto out;
1081 
1082 	desc_id = dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_ID)
1083 		& XILINX_DPDMA_CH_DESC_ID_MASK;
1084 
1085 	/* If the retrigger raced with vsync, retry at the next frame. */
1086 	sw_desc = list_first_entry(&pending->descriptors,
1087 				   struct xilinx_dpdma_sw_desc, node);
1088 	if (sw_desc->hw.desc_id != desc_id) {
1089 		dev_dbg(chan->xdev->dev,
1090 			"chan%u: vsync race lost (%u != %u), retrying\n",
1091 			chan->id, sw_desc->hw.desc_id, desc_id);
1092 		goto out;
1093 	}
1094 
1095 	/*
1096 	 * Complete the active descriptor, if any, promote the pending
1097 	 * descriptor to active, and queue the next transfer, if any.
1098 	 */
1099 	spin_lock(&chan->vchan.lock);
1100 	if (chan->desc.active)
1101 		vchan_cookie_complete(&chan->desc.active->vdesc);
1102 	chan->desc.active = pending;
1103 	chan->desc.pending = NULL;
1104 
1105 	xilinx_dpdma_chan_queue_transfer(chan);
1106 	spin_unlock(&chan->vchan.lock);
1107 
1108 out:
1109 	spin_unlock(&chan->lock);
1110 }
1111 
1112 /**
1113  * xilinx_dpdma_chan_err - Detect any channel error
1114  * @chan: DPDMA channel
1115  * @isr: masked Interrupt Status Register
1116  * @eisr: Error Interrupt Status Register
1117  *
1118  * Return: true if any channel error occurs, or false otherwise.
1119  */
1120 static bool
1121 xilinx_dpdma_chan_err(struct xilinx_dpdma_chan *chan, u32 isr, u32 eisr)
1122 {
1123 	if (!chan)
1124 		return false;
1125 
1126 	if (chan->running &&
1127 	    ((isr & (XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id)) ||
1128 	    (eisr & (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id))))
1129 		return true;
1130 
1131 	return false;
1132 }
1133 
1134 /**
1135  * xilinx_dpdma_chan_handle_err - DPDMA channel error handling
1136  * @chan: DPDMA channel
1137  *
1138  * This function is called when any channel error or any global error occurs.
1139  * The function disables the paused channel by errors and determines
1140  * if the current active descriptor can be rescheduled depending on
1141  * the descriptor status.
1142  */
1143 static void xilinx_dpdma_chan_handle_err(struct xilinx_dpdma_chan *chan)
1144 {
1145 	struct xilinx_dpdma_device *xdev = chan->xdev;
1146 	struct xilinx_dpdma_tx_desc *active;
1147 	unsigned long flags;
1148 
1149 	spin_lock_irqsave(&chan->lock, flags);
1150 
1151 	dev_dbg(xdev->dev, "chan%u: cur desc addr = 0x%04x%08x\n",
1152 		chan->id,
1153 		dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE),
1154 		dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR));
1155 	dev_dbg(xdev->dev, "chan%u: cur payload addr = 0x%04x%08x\n",
1156 		chan->id,
1157 		dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDRE),
1158 		dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDR));
1159 
1160 	xilinx_dpdma_chan_disable(chan);
1161 	chan->running = false;
1162 
1163 	if (!chan->desc.active)
1164 		goto out_unlock;
1165 
1166 	active = chan->desc.active;
1167 	chan->desc.active = NULL;
1168 
1169 	xilinx_dpdma_chan_dump_tx_desc(chan, active);
1170 
1171 	if (active->error)
1172 		dev_dbg(xdev->dev, "chan%u: repeated error on desc\n",
1173 			chan->id);
1174 
1175 	/* Reschedule if there's no new descriptor */
1176 	if (!chan->desc.pending &&
1177 	    list_empty(&chan->vchan.desc_issued)) {
1178 		active->error = true;
1179 		list_add_tail(&active->vdesc.node,
1180 			      &chan->vchan.desc_issued);
1181 	} else {
1182 		xilinx_dpdma_chan_free_tx_desc(&active->vdesc);
1183 	}
1184 
1185 out_unlock:
1186 	spin_unlock_irqrestore(&chan->lock, flags);
1187 }
1188 
1189 /* -----------------------------------------------------------------------------
1190  * DMA Engine Operations
1191  */
1192 
1193 static struct dma_async_tx_descriptor *
1194 xilinx_dpdma_prep_interleaved_dma(struct dma_chan *dchan,
1195 				  struct dma_interleaved_template *xt,
1196 				  unsigned long flags)
1197 {
1198 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1199 	struct xilinx_dpdma_tx_desc *desc;
1200 
1201 	if (xt->dir != DMA_MEM_TO_DEV)
1202 		return NULL;
1203 
1204 	if (!xt->numf || !xt->sgl[0].size)
1205 		return NULL;
1206 
1207 	if (!(flags & DMA_PREP_REPEAT) || !(flags & DMA_PREP_LOAD_EOT))
1208 		return NULL;
1209 
1210 	desc = xilinx_dpdma_chan_prep_interleaved_dma(chan, xt);
1211 	if (!desc)
1212 		return NULL;
1213 
1214 	vchan_tx_prep(&chan->vchan, &desc->vdesc, flags | DMA_CTRL_ACK);
1215 
1216 	return &desc->vdesc.tx;
1217 }
1218 
1219 /**
1220  * xilinx_dpdma_alloc_chan_resources - Allocate resources for the channel
1221  * @dchan: DMA channel
1222  *
1223  * Allocate a descriptor pool for the channel.
1224  *
1225  * Return: 0 on success, or -ENOMEM if failed to allocate a pool.
1226  */
1227 static int xilinx_dpdma_alloc_chan_resources(struct dma_chan *dchan)
1228 {
1229 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1230 	size_t align = __alignof__(struct xilinx_dpdma_sw_desc);
1231 
1232 	chan->desc_pool = dma_pool_create(dev_name(chan->xdev->dev),
1233 					  chan->xdev->dev,
1234 					  sizeof(struct xilinx_dpdma_sw_desc),
1235 					  align, 0);
1236 	if (!chan->desc_pool) {
1237 		dev_err(chan->xdev->dev,
1238 			"chan%u: failed to allocate a descriptor pool\n",
1239 			chan->id);
1240 		return -ENOMEM;
1241 	}
1242 
1243 	return 0;
1244 }
1245 
1246 /**
1247  * xilinx_dpdma_free_chan_resources - Free all resources for the channel
1248  * @dchan: DMA channel
1249  *
1250  * Free resources associated with the virtual DMA channel, and destroy the
1251  * descriptor pool.
1252  */
1253 static void xilinx_dpdma_free_chan_resources(struct dma_chan *dchan)
1254 {
1255 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1256 
1257 	vchan_free_chan_resources(&chan->vchan);
1258 
1259 	dma_pool_destroy(chan->desc_pool);
1260 	chan->desc_pool = NULL;
1261 }
1262 
1263 static void xilinx_dpdma_issue_pending(struct dma_chan *dchan)
1264 {
1265 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1266 	unsigned long flags;
1267 
1268 	spin_lock_irqsave(&chan->lock, flags);
1269 	spin_lock(&chan->vchan.lock);
1270 	if (vchan_issue_pending(&chan->vchan))
1271 		xilinx_dpdma_chan_queue_transfer(chan);
1272 	spin_unlock(&chan->vchan.lock);
1273 	spin_unlock_irqrestore(&chan->lock, flags);
1274 }
1275 
1276 static int xilinx_dpdma_config(struct dma_chan *dchan,
1277 			       struct dma_slave_config *config)
1278 {
1279 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1280 	struct xilinx_dpdma_peripheral_config *pconfig;
1281 	unsigned long flags;
1282 
1283 	/*
1284 	 * The destination address doesn't need to be specified as the DPDMA is
1285 	 * hardwired to the destination (the DP controller). The transfer
1286 	 * width, burst size and port window size are thus meaningless, they're
1287 	 * fixed both on the DPDMA side and on the DP controller side.
1288 	 */
1289 
1290 	/*
1291 	 * Use the peripheral_config to indicate that the channel is part
1292 	 * of a video group. This requires matching use of the custom
1293 	 * structure in each driver.
1294 	 */
1295 	pconfig = config->peripheral_config;
1296 	if (WARN_ON(pconfig && config->peripheral_size != sizeof(*pconfig)))
1297 		return -EINVAL;
1298 
1299 	spin_lock_irqsave(&chan->lock, flags);
1300 	if (chan->id <= ZYNQMP_DPDMA_VIDEO2 && pconfig)
1301 		chan->video_group = pconfig->video_group;
1302 	spin_unlock_irqrestore(&chan->lock, flags);
1303 
1304 	return 0;
1305 }
1306 
1307 static int xilinx_dpdma_pause(struct dma_chan *dchan)
1308 {
1309 	xilinx_dpdma_chan_pause(to_xilinx_chan(dchan));
1310 
1311 	return 0;
1312 }
1313 
1314 static int xilinx_dpdma_resume(struct dma_chan *dchan)
1315 {
1316 	xilinx_dpdma_chan_unpause(to_xilinx_chan(dchan));
1317 
1318 	return 0;
1319 }
1320 
1321 /**
1322  * xilinx_dpdma_terminate_all - Terminate the channel and descriptors
1323  * @dchan: DMA channel
1324  *
1325  * Pause the channel without waiting for ongoing transfers to complete. Waiting
1326  * for completion is performed by xilinx_dpdma_synchronize() that will disable
1327  * the channel to complete the stop.
1328  *
1329  * All the descriptors associated with the channel that are guaranteed not to
1330  * be touched by the hardware. The pending and active descriptor are not
1331  * touched, and will be freed either upon completion, or by
1332  * xilinx_dpdma_synchronize().
1333  *
1334  * Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
1335  */
1336 static int xilinx_dpdma_terminate_all(struct dma_chan *dchan)
1337 {
1338 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1339 	struct xilinx_dpdma_device *xdev = chan->xdev;
1340 	LIST_HEAD(descriptors);
1341 	unsigned long flags;
1342 	unsigned int i;
1343 
1344 	/* Pause the channel (including the whole video group if applicable). */
1345 	if (chan->video_group) {
1346 		for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
1347 			if (xdev->chan[i]->video_group &&
1348 			    xdev->chan[i]->running) {
1349 				xilinx_dpdma_chan_pause(xdev->chan[i]);
1350 				xdev->chan[i]->video_group = false;
1351 			}
1352 		}
1353 	} else {
1354 		xilinx_dpdma_chan_pause(chan);
1355 	}
1356 
1357 	/* Gather all the descriptors we can free and free them. */
1358 	spin_lock_irqsave(&chan->vchan.lock, flags);
1359 	vchan_get_all_descriptors(&chan->vchan, &descriptors);
1360 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1361 
1362 	vchan_dma_desc_free_list(&chan->vchan, &descriptors);
1363 
1364 	return 0;
1365 }
1366 
1367 /**
1368  * xilinx_dpdma_synchronize - Synchronize callback execution
1369  * @dchan: DMA channel
1370  *
1371  * Synchronizing callback execution ensures that all previously issued
1372  * transfers have completed and all associated callbacks have been called and
1373  * have returned.
1374  *
1375  * This function waits for the DMA channel to stop. It assumes it has been
1376  * paused by a previous call to dmaengine_terminate_async(), and that no new
1377  * pending descriptors have been issued with dma_async_issue_pending(). The
1378  * behaviour is undefined otherwise.
1379  */
1380 static void xilinx_dpdma_synchronize(struct dma_chan *dchan)
1381 {
1382 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1383 	unsigned long flags;
1384 
1385 	xilinx_dpdma_chan_stop(chan);
1386 
1387 	spin_lock_irqsave(&chan->vchan.lock, flags);
1388 	if (chan->desc.pending) {
1389 		vchan_terminate_vdesc(&chan->desc.pending->vdesc);
1390 		chan->desc.pending = NULL;
1391 	}
1392 	if (chan->desc.active) {
1393 		vchan_terminate_vdesc(&chan->desc.active->vdesc);
1394 		chan->desc.active = NULL;
1395 	}
1396 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1397 
1398 	vchan_synchronize(&chan->vchan);
1399 }
1400 
1401 /* -----------------------------------------------------------------------------
1402  * Interrupt and Tasklet Handling
1403  */
1404 
1405 /**
1406  * xilinx_dpdma_err - Detect any global error
1407  * @isr: Interrupt Status Register
1408  * @eisr: Error Interrupt Status Register
1409  *
1410  * Return: True if any global error occurs, or false otherwise.
1411  */
1412 static bool xilinx_dpdma_err(u32 isr, u32 eisr)
1413 {
1414 	if (isr & XILINX_DPDMA_INTR_GLOBAL_ERR ||
1415 	    eisr & XILINX_DPDMA_EINTR_GLOBAL_ERR)
1416 		return true;
1417 
1418 	return false;
1419 }
1420 
1421 /**
1422  * xilinx_dpdma_handle_err_irq - Handle DPDMA error interrupt
1423  * @xdev: DPDMA device
1424  * @isr: masked Interrupt Status Register
1425  * @eisr: Error Interrupt Status Register
1426  *
1427  * Handle if any error occurs based on @isr and @eisr. This function disables
1428  * corresponding error interrupts, and those should be re-enabled once handling
1429  * is done.
1430  */
1431 static void xilinx_dpdma_handle_err_irq(struct xilinx_dpdma_device *xdev,
1432 					u32 isr, u32 eisr)
1433 {
1434 	bool err = xilinx_dpdma_err(isr, eisr);
1435 	unsigned int i;
1436 
1437 	dev_dbg_ratelimited(xdev->dev,
1438 			    "error irq: isr = 0x%08x, eisr = 0x%08x\n",
1439 			    isr, eisr);
1440 
1441 	/* Disable channel error interrupts until errors are handled. */
1442 	dpdma_write(xdev->reg, XILINX_DPDMA_IDS,
1443 		    isr & ~XILINX_DPDMA_INTR_GLOBAL_ERR);
1444 	dpdma_write(xdev->reg, XILINX_DPDMA_EIDS,
1445 		    eisr & ~XILINX_DPDMA_EINTR_GLOBAL_ERR);
1446 
1447 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1448 		if (err || xilinx_dpdma_chan_err(xdev->chan[i], isr, eisr))
1449 			tasklet_schedule(&xdev->chan[i]->err_task);
1450 }
1451 
1452 /**
1453  * xilinx_dpdma_enable_irq - Enable interrupts
1454  * @xdev: DPDMA device
1455  *
1456  * Enable interrupts.
1457  */
1458 static void xilinx_dpdma_enable_irq(struct xilinx_dpdma_device *xdev)
1459 {
1460 	dpdma_write(xdev->reg, XILINX_DPDMA_IEN, XILINX_DPDMA_INTR_ALL);
1461 	dpdma_write(xdev->reg, XILINX_DPDMA_EIEN, XILINX_DPDMA_EINTR_ALL);
1462 }
1463 
1464 /**
1465  * xilinx_dpdma_disable_irq - Disable interrupts
1466  * @xdev: DPDMA device
1467  *
1468  * Disable interrupts.
1469  */
1470 static void xilinx_dpdma_disable_irq(struct xilinx_dpdma_device *xdev)
1471 {
1472 	dpdma_write(xdev->reg, XILINX_DPDMA_IDS, XILINX_DPDMA_INTR_ALL);
1473 	dpdma_write(xdev->reg, XILINX_DPDMA_EIDS, XILINX_DPDMA_EINTR_ALL);
1474 }
1475 
1476 /**
1477  * xilinx_dpdma_chan_err_task - Per channel tasklet for error handling
1478  * @t: pointer to the tasklet associated with this handler
1479  *
1480  * Per channel error handling tasklet. This function waits for the outstanding
1481  * transaction to complete and triggers error handling. After error handling,
1482  * re-enable channel error interrupts, and restart the channel if needed.
1483  */
1484 static void xilinx_dpdma_chan_err_task(struct tasklet_struct *t)
1485 {
1486 	struct xilinx_dpdma_chan *chan = from_tasklet(chan, t, err_task);
1487 	struct xilinx_dpdma_device *xdev = chan->xdev;
1488 	unsigned long flags;
1489 
1490 	/* Proceed error handling even when polling fails. */
1491 	xilinx_dpdma_chan_poll_no_ostand(chan);
1492 
1493 	xilinx_dpdma_chan_handle_err(chan);
1494 
1495 	dpdma_write(xdev->reg, XILINX_DPDMA_IEN,
1496 		    XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id);
1497 	dpdma_write(xdev->reg, XILINX_DPDMA_EIEN,
1498 		    XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id);
1499 
1500 	spin_lock_irqsave(&chan->lock, flags);
1501 	spin_lock(&chan->vchan.lock);
1502 	xilinx_dpdma_chan_queue_transfer(chan);
1503 	spin_unlock(&chan->vchan.lock);
1504 	spin_unlock_irqrestore(&chan->lock, flags);
1505 }
1506 
1507 static irqreturn_t xilinx_dpdma_irq_handler(int irq, void *data)
1508 {
1509 	struct xilinx_dpdma_device *xdev = data;
1510 	unsigned long mask;
1511 	unsigned int i;
1512 	u32 status;
1513 	u32 error;
1514 
1515 	status = dpdma_read(xdev->reg, XILINX_DPDMA_ISR);
1516 	error = dpdma_read(xdev->reg, XILINX_DPDMA_EISR);
1517 	if (!status && !error)
1518 		return IRQ_NONE;
1519 
1520 	dpdma_write(xdev->reg, XILINX_DPDMA_ISR, status);
1521 	dpdma_write(xdev->reg, XILINX_DPDMA_EISR, error);
1522 
1523 	if (status & XILINX_DPDMA_INTR_VSYNC) {
1524 		/*
1525 		 * There's a single VSYNC interrupt that needs to be processed
1526 		 * by each running channel to update the active descriptor.
1527 		 */
1528 		for (i = 0; i < ARRAY_SIZE(xdev->chan); i++) {
1529 			struct xilinx_dpdma_chan *chan = xdev->chan[i];
1530 
1531 			if (chan)
1532 				xilinx_dpdma_chan_vsync_irq(chan);
1533 		}
1534 	}
1535 
1536 	mask = FIELD_GET(XILINX_DPDMA_INTR_DESC_DONE_MASK, status);
1537 	if (mask) {
1538 		for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
1539 			xilinx_dpdma_chan_done_irq(xdev->chan[i]);
1540 	}
1541 
1542 	mask = FIELD_GET(XILINX_DPDMA_INTR_NO_OSTAND_MASK, status);
1543 	if (mask) {
1544 		for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
1545 			xilinx_dpdma_chan_notify_no_ostand(xdev->chan[i]);
1546 	}
1547 
1548 	mask = status & XILINX_DPDMA_INTR_ERR_ALL;
1549 	if (mask || error)
1550 		xilinx_dpdma_handle_err_irq(xdev, mask, error);
1551 
1552 	return IRQ_HANDLED;
1553 }
1554 
1555 /* -----------------------------------------------------------------------------
1556  * Initialization & Cleanup
1557  */
1558 
1559 static int xilinx_dpdma_chan_init(struct xilinx_dpdma_device *xdev,
1560 				  unsigned int chan_id)
1561 {
1562 	struct xilinx_dpdma_chan *chan;
1563 
1564 	chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL);
1565 	if (!chan)
1566 		return -ENOMEM;
1567 
1568 	chan->id = chan_id;
1569 	chan->reg = xdev->reg + XILINX_DPDMA_CH_BASE
1570 		  + XILINX_DPDMA_CH_OFFSET * chan->id;
1571 	chan->running = false;
1572 	chan->xdev = xdev;
1573 
1574 	spin_lock_init(&chan->lock);
1575 	init_waitqueue_head(&chan->wait_to_stop);
1576 
1577 	tasklet_setup(&chan->err_task, xilinx_dpdma_chan_err_task);
1578 
1579 	chan->vchan.desc_free = xilinx_dpdma_chan_free_tx_desc;
1580 	vchan_init(&chan->vchan, &xdev->common);
1581 
1582 	xdev->chan[chan->id] = chan;
1583 
1584 	return 0;
1585 }
1586 
1587 static void xilinx_dpdma_chan_remove(struct xilinx_dpdma_chan *chan)
1588 {
1589 	if (!chan)
1590 		return;
1591 
1592 	tasklet_kill(&chan->err_task);
1593 	list_del(&chan->vchan.chan.device_node);
1594 }
1595 
1596 static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
1597 					    struct of_dma *ofdma)
1598 {
1599 	struct xilinx_dpdma_device *xdev = ofdma->of_dma_data;
1600 	u32 chan_id = dma_spec->args[0];
1601 
1602 	if (chan_id >= ARRAY_SIZE(xdev->chan))
1603 		return NULL;
1604 
1605 	if (!xdev->chan[chan_id])
1606 		return NULL;
1607 
1608 	return dma_get_slave_channel(&xdev->chan[chan_id]->vchan.chan);
1609 }
1610 
1611 static void dpdma_hw_init(struct xilinx_dpdma_device *xdev)
1612 {
1613 	unsigned int i;
1614 	void __iomem *reg;
1615 
1616 	/* Disable all interrupts */
1617 	xilinx_dpdma_disable_irq(xdev);
1618 
1619 	/* Stop all channels */
1620 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++) {
1621 		reg = xdev->reg + XILINX_DPDMA_CH_BASE
1622 				+ XILINX_DPDMA_CH_OFFSET * i;
1623 		dpdma_clr(reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_ENABLE);
1624 	}
1625 
1626 	/* Clear the interrupt status registers */
1627 	dpdma_write(xdev->reg, XILINX_DPDMA_ISR, XILINX_DPDMA_INTR_ALL);
1628 	dpdma_write(xdev->reg, XILINX_DPDMA_EISR, XILINX_DPDMA_EINTR_ALL);
1629 }
1630 
1631 static int xilinx_dpdma_probe(struct platform_device *pdev)
1632 {
1633 	struct xilinx_dpdma_device *xdev;
1634 	struct dma_device *ddev;
1635 	unsigned int i;
1636 	int ret;
1637 
1638 	xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
1639 	if (!xdev)
1640 		return -ENOMEM;
1641 
1642 	xdev->dev = &pdev->dev;
1643 	xdev->ext_addr = sizeof(dma_addr_t) > 4;
1644 
1645 	INIT_LIST_HEAD(&xdev->common.channels);
1646 
1647 	platform_set_drvdata(pdev, xdev);
1648 
1649 	xdev->axi_clk = devm_clk_get(xdev->dev, "axi_clk");
1650 	if (IS_ERR(xdev->axi_clk))
1651 		return PTR_ERR(xdev->axi_clk);
1652 
1653 	xdev->reg = devm_platform_ioremap_resource(pdev, 0);
1654 	if (IS_ERR(xdev->reg))
1655 		return PTR_ERR(xdev->reg);
1656 
1657 	dpdma_hw_init(xdev);
1658 
1659 	xdev->irq = platform_get_irq(pdev, 0);
1660 	if (xdev->irq < 0)
1661 		return xdev->irq;
1662 
1663 	ret = request_irq(xdev->irq, xilinx_dpdma_irq_handler, IRQF_SHARED,
1664 			  dev_name(xdev->dev), xdev);
1665 	if (ret) {
1666 		dev_err(xdev->dev, "failed to request IRQ\n");
1667 		return ret;
1668 	}
1669 
1670 	ddev = &xdev->common;
1671 	ddev->dev = &pdev->dev;
1672 
1673 	dma_cap_set(DMA_SLAVE, ddev->cap_mask);
1674 	dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
1675 	dma_cap_set(DMA_INTERLEAVE, ddev->cap_mask);
1676 	dma_cap_set(DMA_REPEAT, ddev->cap_mask);
1677 	dma_cap_set(DMA_LOAD_EOT, ddev->cap_mask);
1678 	ddev->copy_align = fls(XILINX_DPDMA_ALIGN_BYTES - 1);
1679 
1680 	ddev->device_alloc_chan_resources = xilinx_dpdma_alloc_chan_resources;
1681 	ddev->device_free_chan_resources = xilinx_dpdma_free_chan_resources;
1682 	ddev->device_prep_interleaved_dma = xilinx_dpdma_prep_interleaved_dma;
1683 	/* TODO: Can we achieve better granularity ? */
1684 	ddev->device_tx_status = dma_cookie_status;
1685 	ddev->device_issue_pending = xilinx_dpdma_issue_pending;
1686 	ddev->device_config = xilinx_dpdma_config;
1687 	ddev->device_pause = xilinx_dpdma_pause;
1688 	ddev->device_resume = xilinx_dpdma_resume;
1689 	ddev->device_terminate_all = xilinx_dpdma_terminate_all;
1690 	ddev->device_synchronize = xilinx_dpdma_synchronize;
1691 	ddev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED);
1692 	ddev->directions = BIT(DMA_MEM_TO_DEV);
1693 	ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1694 
1695 	for (i = 0; i < ARRAY_SIZE(xdev->chan); ++i) {
1696 		ret = xilinx_dpdma_chan_init(xdev, i);
1697 		if (ret < 0) {
1698 			dev_err(xdev->dev, "failed to initialize channel %u\n",
1699 				i);
1700 			goto error;
1701 		}
1702 	}
1703 
1704 	ret = clk_prepare_enable(xdev->axi_clk);
1705 	if (ret) {
1706 		dev_err(xdev->dev, "failed to enable the axi clock\n");
1707 		goto error;
1708 	}
1709 
1710 	ret = dma_async_device_register(ddev);
1711 	if (ret) {
1712 		dev_err(xdev->dev, "failed to register the dma device\n");
1713 		goto error_dma_async;
1714 	}
1715 
1716 	ret = of_dma_controller_register(xdev->dev->of_node,
1717 					 of_dma_xilinx_xlate, ddev);
1718 	if (ret) {
1719 		dev_err(xdev->dev, "failed to register DMA to DT DMA helper\n");
1720 		goto error_of_dma;
1721 	}
1722 
1723 	xilinx_dpdma_enable_irq(xdev);
1724 
1725 	xilinx_dpdma_debugfs_init(xdev);
1726 
1727 	dev_info(&pdev->dev, "Xilinx DPDMA engine is probed\n");
1728 
1729 	return 0;
1730 
1731 error_of_dma:
1732 	dma_async_device_unregister(ddev);
1733 error_dma_async:
1734 	clk_disable_unprepare(xdev->axi_clk);
1735 error:
1736 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1737 		xilinx_dpdma_chan_remove(xdev->chan[i]);
1738 
1739 	free_irq(xdev->irq, xdev);
1740 
1741 	return ret;
1742 }
1743 
1744 static void xilinx_dpdma_remove(struct platform_device *pdev)
1745 {
1746 	struct xilinx_dpdma_device *xdev = platform_get_drvdata(pdev);
1747 	unsigned int i;
1748 
1749 	/* Start by disabling the IRQ to avoid races during cleanup. */
1750 	free_irq(xdev->irq, xdev);
1751 
1752 	xilinx_dpdma_disable_irq(xdev);
1753 	of_dma_controller_free(pdev->dev.of_node);
1754 	dma_async_device_unregister(&xdev->common);
1755 	clk_disable_unprepare(xdev->axi_clk);
1756 
1757 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1758 		xilinx_dpdma_chan_remove(xdev->chan[i]);
1759 }
1760 
1761 static const struct of_device_id xilinx_dpdma_of_match[] = {
1762 	{ .compatible = "xlnx,zynqmp-dpdma",},
1763 	{ /* end of table */ },
1764 };
1765 MODULE_DEVICE_TABLE(of, xilinx_dpdma_of_match);
1766 
1767 static struct platform_driver xilinx_dpdma_driver = {
1768 	.probe			= xilinx_dpdma_probe,
1769 	.remove_new		= xilinx_dpdma_remove,
1770 	.driver			= {
1771 		.name		= "xilinx-zynqmp-dpdma",
1772 		.of_match_table	= xilinx_dpdma_of_match,
1773 	},
1774 };
1775 
1776 module_platform_driver(xilinx_dpdma_driver);
1777 
1778 MODULE_AUTHOR("Xilinx, Inc.");
1779 MODULE_DESCRIPTION("Xilinx ZynqMP DPDMA driver");
1780 MODULE_LICENSE("GPL v2");
1781